Minor Description
TestDatanodeStartupFixesLegacyStorageIDs#testUpgradeFrom22via26FixesStorageIDs uses a checked-in DataNode data directory that contains hard links. The hard links cannot be handled correctly by the commons-compress library used in the Windows implementation of FileUtil#unTar. The result is that the unpacked block files have 0 length, the block files reported to the NameNode are invalid, and therefore the mini-cluster never gets enough good blocks reported to leave safe mode.
